The present invention relates to cast iron pipe fittings and related methods for coupling, and particularly relates to fittings useful in fluid flow networks where reductions in flow through branch conduits are necessary and desirable.
Many and various types of fluid handling networks are known. For example, a fluid handling network may comprise a pipe system for irrigating a golf course. Depending upon the proximity to the source of fluid, the pipes forming the network branch from the fluid source into various pipe sections, typically of decreasing diameter. Those pipe sections extend in a plurality of different directions and likewise branch into additional pipe sections of decreasing diameter. Fittings are employed to (i) connect the pipe sections one to the other, (ii) reduce the diameter of the pipe sections and (iii) enable the pipe sections to extend in different directions. Fittings for this purpose are typically supplied in various configurations, such as Tees, elbows, right-angle bends, bends at acute angles, etc., with one or more of the openings of the fittings having a diameter the same as or different than the diameters of other of the openings.
A manufacturer or supplier of fittings may stock a very substantial number of sizes of the various fittings or have sufficient patterns available to manufacture on demand the various sizes of fittings required to accommodate most but not all of the requirements for fittings for various fluid handling networks. For example, in the representative example of the irrigation system for a golf course, dozens of standard fittings are required, along with a substantial number of specialty or customized fittings to meet the requirements of the particular fluid handling network. Thus, a manufacturer or supplier of pipe fittings may have in inventory the standard fittings needed for the construction of a particular irrigation project, but the cost of such inventory would be quite substantial, if not prohibitive. Even if an inventory of standard fittings is not maintained, the cost of obtaining various patterns from which those standard fittings can be manufactured on demand is substantial.
Aside from the substantial expense of maintaining an inventory of fittings or bearing the cost of a substantial number of patterns, the number of non-standard or custom fittings required for each different project poses a particular problem for the supplier of the fittings. While the supplier may justify purchasing patterns for relatively standard fittings, it is burdensome to obtain a pattern for a special or custom fitting when only a couple of fittings will be sold for a particular system. The investment costs are simply too substantial.
In an effort to solve this and other problems, plastic fittings, for example, PVC, have been used. This has resulted in decreased production and tooling costs as plastic tends to be more readily amenable to producing standard, as well as specialty, fittings. However, plastic fittings have been shown to be disadvantageous in certain aspects and the industry still prefers the cast iron fitting.
The present invention therefore provides cast iron fittings and a related method of coupling the fittings into a fluid supply network which minimizes or eliminates the foregoing and other problems and disadvantages associated with prior art fittings and provides novel and improved fittings for facilitating the design and construction of fluid supply networks as well as to reduce the cost associated with its construction. According to the present invention, there is provided a pipe coupling system using cast iron standard main fittings in combination with cast iron reducer fittings. It will be appreciated that the standard main fittings, whether they be Tees, bends, elbows, etc., comprise fittings with two or more ends which may have the same or different diameters relative to one another. Thus, a main fitting can be employed for reducing the flow diameter, for example, from a 12-inch flow to an 8-inch flow. A reducer fitting, according to the present invention, is a straight pipe section having opposite ends of different diameters. Instead of manufacturing and supplying a large number of expensive standard main fittings with various diameter openings at the ends thereof (the number of combinations and permutations of which is very substantial), the present invention employs reducer fittings which can be manufactured simply, inexpensively and in discrete sizes to reduce the flow diameters flowing through the outlet openings of the main fittings. For example, reducer fittings having a predetermined diameter opening at one end may be provided with different-sized openings at its opposite end. Consequently, a selected reducer fitting may be used in conjunction with a standard main fitting for reducing the flow to the desired flow diameter, depending upon the selection of the reducer fitting.
Thus, by providing a number of basic patterns of main fittings and combining them with one or more of the variously sized reducer fittings, it is possible to create a large number of diameter combinations. Moreover, all configurations can be factory or field-assembled and jobs need not be delayed pending fabrication of specialized fittings. Additionally, if a combined fitting is not used on the job, it can be broken down into the standard main-fitting and reducer fitting for subsequent use. This flexibility benefits designer, contractors and suppliers because it allows changes to be made in the field, reduces the amount of inventory and minimization or diminution of special or custom fittings.
More specifically, where a main Tee-fitting is used, the large-diameter end of a reducer fitting may be secured into an end of the Tee-fitting. The opposite end of the reducer fitting with its reduced diameter opening is then connected to a pipe section downstream of the main fitting. For example, a standard main fitting may have a twelve-inch inlet and an eight-inch outlet opening. To reduce the flow even further, a reducer fitting may be selected from a set of reducer fittings or patterns having an eight-inch inlet opening for coupling with the eight-inch outlet opening of the Tee and any lesser size outlet opening, e.g., six, four or two-inch diameter openings. A particular advantage of this system resides in the capability of the manufacturer and supplier of fittings to have an inventory of reducer fittings or patterns therefor of various sizes at a substantially decreased cost in comparison with providing costly main fittings in the various size combinations necessary to provide not only the standard fittings but also the customized and specialized fittings necessary for fluid handling networks. It also reduces the number of different sizes of main fittings necessary to accommodate a particular job.
Moreover, the present invention affords a simplicity of assemblage of the various pipe fittings. For example, at the end of each main fitting, there is provided two or more radially outwardly projecting, circumferentially-spaced lugs. The reducer fitting has a similar number of radially outwardly projecting, circumferentially-spaced lugs at a location spaced back from the cylindrical end of the reducer fitting. The cylindrical end is sized for reception in the bell of the main fitting. Consequently, when the reducer fitting is connected to the main fitting, the cylindrical end is inserted into the bell, and the lugs are aligned one with the other. A metal wrapping or strap is applied to the registering lugs to secure the reducer fitting and main fitting one to the other. Similar reducer fittings may be applied to other openings of each main fitting, it being appreciated that it is essential to secure each reducer fitting to its adjoining main fitting to prevent the flow pressure from axially displacing the reducer fitting downstream from the main fitting.
In a preferred embodiment according to the present invention, there is provided a pipe coupling system for use in a fluid handling network, a cast pipe fitting having a central body with first and second ends having openings therein, the fitting having radially outwardly projecting, circumferentially-spaced, tabs about at least one of the open ends, the tabs defining restraint lugs and being cast integrally with the fitting and means carried by the tabs for joining the fitting to an adjacent fitting, including recessed portions formed on the tabs on the side thereof opposite the associated open end.
In a further preferred embodiment according to the present invention, there is provided a pipe coupling system for use in a fluid handling network, a cast pipe reducer fitting having a central body with first and second ends having openings therein, the first end of the fitting having a diameter larger than the second end thereof whereby the second end defines a reducer flow diameter, the body having a central tapered section between the first and second ends and a cylindrical section extending from the tapered section to the first end thereof, the fitting having radially outwardly projecting, circumferentially-spaced, tabs thereabout and located adjacent the juncture of the tapered and cylindrical sections and the tabs defining restraint lugs and being cast integrally with the fitting.
In a further preferred embodiment according to the present invention, there is provided a pipe coupling system for a fluid handling network comprising a cast pipe fitting having a central body with first and second ends having openings therein, the fitting having radially outwardly projecting, circumferentially-spaced, tabs about each of the open ends, the tabs defining restraint lugs and being cast integrally with the fitting, a reducer fitting having a central body with first and second ends having openings therein with the first end being larger in diameter than the second end, the body having a central tapered section between the first and second ends and a cylindrical section extending from the tapered section to the first end thereof, the reducer fitting having radially outwardly projecting, circumferentially-spaced, tabs thereabout and located adjacent the juncture of the tapered and cylindrical sections, the tabs on the reducer fitting defining restraint lugs cast integrally therewith, the cylindrical section of the reducer fitting being inserted into one of the open ends of the cast pipe fitting, the one end of the cast pipe fitting having a seal for sealing the cylindrical section of the reducer fitting thereto and means for securing the lugs of the cast pipe and reducer fittings one to the other to secure the fittings to one another.
In a further preferred embodiment according to the present invention, there is provided a method of coupling pipes forming a fluid handling network comprising the steps of providing a cast pipe fitting having a central body with first and second ends having openings therein, the fitting having radially outwardly projecting, circumferentially-spaced, tabs about the openings defining restraint lugs, providing a reducer fitting having a central body with first and second open ends, the first end having a diameter larger than the second end, the reducer fitting having radially outwardly projecting, circumferentially-spaced, tabs thereon defining restraint lugs located intermediate the ends and which lugs have recessed portions formed on sides thereof opposite adjacent open ends, inserting the first end of the reducer fitting into the first end of the cast pipe fitting, aligning the tabs of the cast pipe fitting about the first end thereof and the tabs about the reducer fitting one with the other and securing the aligned tabs one to the other by wrapping flexible elements about the aligned tabs.
These and further objects and advantages of the present invention will become more apparent upon reference to the following specification, appended claims and drawings.